The Mexican's first goal of the campaign came so early in the second-half, United manager David Moyes had barely got beyond the penalty area in his walk to the home dug-out.

It meant it was easy to spot the Scot's celebration, at a strike that should at least quell some of the angst that built up following that awful hammering at Manchester City four days ago.

United's performance was not perfect.

Indeed, on his return following a 10-match suspension, Luis Suarez came close to levelling when his vicious free-kick struck the bar with David De Gea beaten.

De Gea had only just repelled Victor Moses' powerful diving header.

But the hosts had chances to sew up the contest too, with Simon Mignolet producing a couple of excellent saves to deny Rooney.

And after bravely riding the hefty punches landed on him at the Etihad Stadium, Moyes was probably not that bothered about the actual scoreline anyway, just the much-needed victory against one of England's biggest clubs, and United's greatest rivals.

It was hardly a surprise Suarez should start.

After all, when you have spent so long out and are desperately in need of match fitness, there is little to be gained by kicking your heels on the bench watching others do what you are paid so much for.

Perhaps understandably though, the Uruguayan was not quite on top form.

He was caught on his heels slightly when Steven Gerrard rolled an inviting pass into his path, which allowed Rafael to slide back and clear.

And when Enrique's curling cross dropped over Jonny Evans' head, Suarez's first touch was just too long so De Gea was able to slide out to bravely block his second.

He did supply the through ball that ended with Daniel Sturridge toe-poking wide.

Suarez would have also got the assist if Moses had been able to drill his square ball home. Moses didn't get the opportunity though as Ryan Giggs reached it first.

It was all part of an absorbing opening period, notable for the fact neither goalkeeper actually had a shot to save.

As befitting a team that got so badly beaten at the weekend, and containing so many players with so much to prove, United started with intent.

However, with the exception of a Nani effort that was deflected wide, all that early pressure fizzled out and it wasn't until much later in the half United started to force the pace again.

Yet they did appear to lack conviction, with neither Phil Jones nor Giggs willing to commit fully to attack.

Such tentativeness was perhaps understandable given the hammering meted out at the weekend.

Some kind of relief was required. And it arrived through Hernandez's goal a minute after the re-start.

Liverpool responded to the setback with impressive vigour.

Indeed, they should have been level when United's defence got themselves in a muddle attempting to subdue a joint raid involving Suarez and Sturridge and succeeded only in presenting Jordan Henderson with a shooting chance.

The England man had enough time to do better than merely drag a disappointing shot wide. And he knew it.

Excellent approach play involving Hernandez and Kagawa deserved a better ending than Nani's poor finish too as the second-period delivered the goalmouth action that had been lacking beforehand.

Kagawa, proving exactly why so many United fans were baffled at his lack of action so far this term, saw his dipping effort flick off the bar before play immediately switched to the other end, where Enrique fired wide.

So unhappy was Gerrard with that waste of possession that he very publicly rebuked his team-mate, who kept his head down as he ran back to his defensive station.

It was the prelude to a thrilling finish, in which Moses, Suarez and Rooney, twice, all came close.

In the end though, United held Liverpool at bay for what could turn out to be a very valuable victory for their manager.